This invention is in the field of dentistry. In the filing or reaming of the root canals of endodontically involved teeth, it is important to limit the depth of penetration of the file or reamer used to avoid injury. A typical file includes an adjustable depth stop. During such treatments there are often interruptions to make the accurate determination and control over the depth to which the file or reamer is to be inserted. The dentist must oftentimes stop, make a depth determination or adjustment from other measuring instruments and then return to the treatment. This is time-consuming and inefficient. Such endodontic measurement systems and tools are shown, for example, in the following U.S. Pat. Nos.:
3,562,913 Saffro PA1 3,713,221 Malmin PA1 3,855,705 Malmin